Optical coherence tomography (OCT) is a catheter-based tomographic procedure, which is used—among other things—for obtaining two-dimensional vascular images in vivo. The catheter-guided image recording units used are very narrow wires with integrated optical fibers, via which optical fibers light is emitted in the near infrared range (approx. 1300 nm) and the reflection from the vascular wall is registered with depth resolution by means of inferometry. By translating the radiated light beam, information is obtained from various adjacent parts of the vascular wall and combined into a two-dimensional image covering a large-area.